Getting a color value from a bitmap

[Duane Pederson]

I'm trying to use the bitmap_colors_get() function:

dim ff as P
dim bb as B
dim cc as C
ff = file.open("C:\2622.bmp",FILE_RO_EXCLUSIVE)
bb = ff.readb(1000)
cc = bitmap_colors_get(bb,"B",.t.)

?cc

And as advertised I got a 1000 charachter return

But it's a continuous stream of numbers
The bitmap is an image of a green backdrop
I don't see any number pattern in the data stream

I don't see any reference to the number pattern in any help file

Does anyone know how I can break this result down so I can use the result?

Thanks
Duane

[Stan Mathews]

Re: Getting a color value from a bitmap

Does anyone know how I can break this result down so I can use the result?

What is it you want to do? (with the result)

[Duane Pederson]

Re: Getting a color value from a bitmap

Morning Stan

What I'd like to do is photograph a color checker card, then query the image 3 times, once with each of the Red, Green, and Blue choices.

Then be able to figure out how close the grey patch values are to the mfgr's specs
This will allow me to ensure multi camera setups are going to output the same brightness of image
Even though we're using flash meters to measure our lights to 1/10 of a stop there are still inconsistancies in cameras and lenses.

It doesn't matter if the result values are 0-255, or an 8 bit value, whatever standard it is
I know the pixel dimensions of the camera sensor, and should be able to figure out which sensor pixels (from the result data stream) I'm getting info for; therefore which color patch is being represented. Take an average of numerous data and then get my numerical rep of the color patch. (I'm hoping, anyway)

I know you can buy software to do this procedure, but we're shooting into an A5 app, and I thought is would be very smooth if this process could be built into it

Thanks
Duane

[Stan Mathews]

Re: Getting a color value from a bitmap

Not sure if this will help because I have no idea what the results mean.

dim ff as P
dim bb as B
dim cc as C

ff = file.open("C:\windows\Blue Lace 16.bmp",FILE_RO_EXCLUSIVE)
bb = ff.readb(ff.bytes_get())
cc = bitmap_colors_get(bb,"B",.t.)
?cc
= "0000128128128128192000255255255255"
cc = bitmap_colors_get(bb,"R",.t.)
?cc
= "0128012801280128192255025502550255"

cc = bitmap_colors_get(bb,"G",.t.)
?cc
= "0012812800128128192025525500255255"

ff.close()

Possibly a better example, more colors.

ff = file.open("C:\windows\coffee bean.bmp",FILE_RO_EXCLUSIVE)
bb = ff.readb(ff.bytes_get())
cc = bitmap_colors_get(bb,"B",.t.)
?cc
= "7474666674667474828290748266827490747482666682907457416633669082573366824166824190746641829049578290825774575749748266826657747433577449495749743366997474579090904182905782909999908233664982824190824957906699493374907499419949571076699991074982579090996699908266107826666339949661078290746690994182574182578299576699"
cc = bitmap_colors_get(bb,"R",.t.)
?cc
= "1071159099991079911512311514012313299123901321071231078282115140132825711549115132140905790132661071075712310710749991237490140115132741159974668299741159082132824199908282107661324912314014012366148148140669013282148115123132107123571237414814074107107571159913214874411401159011574132491151487414015614890123107156123148741561561481321321569911566123999911590991401321481154990666614099165165123115132"
cc = bitmap_colors_get(bb,"G",.t.)
?cc
= "829074748282748290901079099829974999099826674829999664190418210710774416610749749049907490418299576699909066997457497474669982749066338282576682571073390107107825710711511557749057107999999828249994911511549907449908299115664199826690571074982123571151231156610774115107107741151231231071071156699499074909066741159012382338249419066123132907490"
ff.close()

[Duane Pederson]

Re: Getting a color value from a bitmap

Stan

That's what I was getting at..... what would those results relate to?

Thanks for checking
Duane

[Stan Mathews]

Re: Getting a color value from a bitmap

what would those results relate to?

Argument
Description

Color_List
A profile of the image data.

More here, wiki entry, and links to the entry about what constitutes a profile.

[G Gabriel]

Re: Getting a color value from a bitmap

That's what I was getting at..... what would those results relate to?

This is binary snippet from the blob.
See if you could convert that to text using:
*bin_to_plain()